obsolete An extremely vile, despicable, and/or worthless person; a person of low birth or esteem; the bastard son of a bastard. "Guillion," a dialectical variation of "cullion," is an archaic term for a contemptible, mean-spirited, or vulgar person; "bastardly" is used to further emphasize this. The scoundrel, the bastardly gullion! He has robbed us of all we own, and after we had the decency of giving him shelter for a night!